Control Method Of6-DOF Manipulator Posture Research And Experiment Based On Sliding Mode Variable Structure

Industrial robot which is most typical electromechanical digital equipment has been broadly used in various industrial product lines. The posture control technology of industrial robot has become an attractive research area at home and abroad. The performance of control system determines whether industrial robot can perform a specific task quickly and accurately. Therefore, it is significant to develop and design various effective industrial robot posture controllers.In this thesis, kinematics model and dynamics model of a six-degree-of-freedom manipulator are given and analyzed. Singular problem and applicable conditions of global fast terminal sliding mode algorithm are developed in detail, and a non-singular global fast terminal sliding mode control algorithm is proposed for a certain joint subsystem of industrial robot. Furthermore, the method is used to design the posture controller of the six-degree-of-freedom manipulator.The connecting rod parameters are obtained by using the improved D-H parameter method after rod coordinate frame of the manipulator is established. And kinematics and dynamics model of the six-degree-of-freedom manipulator is described using the rod transformation matrix and Lagrange method, respectively. Correctness of the model is verified by numerical calculation.The global fast terminal sliding mode control method is analyzed from stability, robustness, singularity, reaching time and sliding mode time, from which applicability of the method is derived. And nonsingular global fast terminal sliding mode control law of joint subsystem is determined by using the Lyapunov theory. In the order to test the effectiveness of control algorithm, the simulation is completed. The results show that it is an effective scheme to consider dynamic equation to be a combination of SISO system, which is multi-variable and strong coupling. Then, the global fast terminal sliding mode control method is used to design controller of each subsystem.Three algorithms are applied to the physical control of six-degree-of-freedom manipulator, which are piecewise function, global fast terminal sliding mode algorithm, and PID algorithm, and experimental data of them are analyzed and compared. What’s more, the six-degree-of-freedom manipulator integrated monitoring interface is developed with the use of software development environment of control system. The experimental results show that the execution efficiency of six-degree-of-freedom manipulator can be improved by using the global fast terminal sliding mode control method.